Multiphase flow conditions complicate production log surveys and their subsequent evaluation. Conventional production log sensors used for fluid identification (nuclear density, gradiomanometer, and capacitance) typically fail or become inaccurate in high watercut environments. For example, capacitance probes become unreliable when the in-situ water fraction or holdup exceeds 40%; i e., the signal is at best qualitative and not quantitatively reliable in locating oil. Density tools such as the gradiomanometer fail when oil density is high (close to water density), the oil fraction is low, and water fraction (holdup) is high. In such cases the gradiomanometer cannot sense oil.